Conventional cattle feeds such as corn and alfalfa often fail to provide sufficient energy for cattle, especially lactating dairy cattle during periods of heavy milk production. Feed containing a high proportion of corn also has a tendency to depress the milk fat content of the milk produced by such cattle. Fat is an excellent energy source, and it is known that if the proportion of fat in cattle food is increased, lactating dairy cattle produce high milk yields without draining their reserves of body fat and without diminishing the proportion of milk fat in the milk produced.
However, it has been found that if the proportion of fat in the diet of cattle exceeds about 3-5% of the total feed solids, the feed has toxic effects upon the microorganisms in the rumen of the cattle. It appears that fat reduces the growth rate or even kills certain microorganisms which digest fiber in the cow's rumen, thereby lowering fiber digestibility. This deleterious effect on the cow's rumen is particularly true of unsaturated fats. Although the decreased fiber digestion in the rumen is partially compensated by greater fiber digestion in the lower parts of the alimentary canal, such later fiber digestion produces a blend of different fatty acids than that which is produced by the digestion in the rumen, and the different blend of fatty acids is less suited to the cow's metabolism.
There has been a continuing need for new fat-containing dietary supplements for animal feed which can be fed to ruminant animals without interfering with the rumen microorganisms.
U.S. Pat. Nos. 4,642,317; 4,826,694; 4,853,233; and 4,909,138 describe the incorporation of insoluble fatty acid salts in ruminant feed as a means of increasing the fat content of the feed without deleteriously affecting the ruminant digestion cycle. A feed additive such as fatty acid calcium salt functions as a rumen-bypass product, and is subsequently metabolized in the abomasum or small intestine of the ruminant.
Similar effort has been directed to the prevention of protein deamination in the rumen of polygastric animals, while preserving the capacity of protein nutrients to be assimilated in the lower regions of the ruminant alimentary tract.
U.S. Pat. Nos. 3,720,765; 3,988,480; 4,211,795; 4,225,620; and 5,064,665 describe methods for producing a protein derivative which has rumen-bypass capability.
One method of providing a rumen-bypass protein is by pelleting soybean meal with lignosulfonate.
GB 2113521 describes a ruminant feedstuff comprising an animal or vegetable protein nutrient ingredient dispersed in a fatty acid alkaline earth metal salt. A feedstuff is obtained by forming a dispersion of protein meal in an aqueous solution of a water-soluble fatty acid salt, and then adding an aqueous solution of basic alkaline earth metal compound to form water-insoluble fatty acid alkaline earth metal salt which precipitates and coats the dispersed protein meal solids. The coated solids have rumen-bypass capability, and are digested in the abomasum or small intestine of ruminants.
Other methods involve the treatment of protein with formaldehyde, or the heat-treatment of protein to cause browning or crosslinking of the protein.
There is sustained interest in the production of dietary feed supplement products which contain fatty acid and/or protein ingredients which exhibit rumen-bypass properties.
Accordingly, it is an object of this invention to provide a fatty acid salt/protein composition which can function as a rumen-bypass dietary supplement for ruminants, and permit a beneficial increase in the dietary fat and protein content of the feed.
It is another object of this invention to provide a fatty acid/protein animal feed supplement for ruminants, which has rumen-bypass properties and which is metabolized in the post-rumen digestive tract of ruminants.
It is another object of this invention to provide an improved process for production of a blend of fatty acid alkaline earth metal salt and denatured protein, utilizing whole oilseed meal as a starting raw material.
Other objects and advantages of the present invention shall become apparent from the accompanying description and example.